Home Brew Octane Booster recipes - what have you got?

shoedoos · Post by **shoedoos** » Mon Sep 28, 2009 2:00 am

Anyone with a home brew recipe for an octane booster, please post it here. Obviously the ingredients need to be readily available.

BGriff · Post by **BGriff** » Mon Sep 28, 2009 7:38 am

Toluene and benzene.
What number are you trying to reach?

SWR · Post by **SWR** » Mon Sep 28, 2009 9:56 am

Ordinary Acetone.. not a wonder-brew or very kind to anything rubber /plastic, but it works...

shoedoos · Post by **shoedoos** » Mon Sep 28, 2009 4:07 pm

BGriff, presently the car runs on 98 octane BP Ultimate pump gas to which we add an off-the-shelf octane booster. I really don't know what the octane booster bumps the rating up to, as the bottle generally just gets thrown in the bin.

The engine is a 470 cube BBC with 12.5 compression in a street driven Camaro.

Nick Campagna · Post by **Nick Campagna** » Mon Sep 28, 2009 8:32 pm

Benzene is cancerous, so be careful. Most boosters say 2 - 3 points which means 100 - 100.3 NOT 100 - 103

BGriff · Post by **BGriff** » Mon Sep 28, 2009 10:14 pm

Forget the off the shelf stuff....waste of money.
Try 15-20% toluene in 93 octane pump gas.
You can purchase it by the gallon or 5 gallon can at the paint or hardware store. Cheaper yet in 55 gallon drum.
Running methanol now, but used up the left over toluene in the tow vehicle mixing 15% in 87 octane pump gas. Truck never ran better.
Do a search for "toluene octane". You'll get plenty of hits, testimonials and formulas.

Rizzle · Post by **Rizzle** » Wed Sep 30, 2009 7:17 pm

The application for the octane booster makes a huge difference in the ability to bump up the rating. At my favorite parts store, they have 2 versions of it on the shelf (NOS). the street version does 6 points, as was mentioned earlier, this doesn't do much, but the race version say 60 points, which becomes a definite boost in octane rating. I am in Canada, and I recall reading somewhere that we are allowed to sell certain octane boosters not available down south, so...?

xanadu · Post by **xanadu** » Thu Oct 01, 2009 6:07 am

That is a great point you make on an octane booster enhancing fuel octane by 1 point as in 0.1. / 93 - 93.1.

Great marketing ploy.

Usually say "UP TO" 6 points or so.
They try and sell it over here for "UP TO" $35 for 600ml.

David Redszus · Post by **David Redszus** » Fri Oct 02, 2009 10:18 am

Toluene and xylene are very useful octane boosters. They have very high octane numbers but are not easy to evaporate. You could use up to 20% of either component.

Do not use benzene, ever. Very bad stuff.

A splash of leaded (118) race fuel will raise octane significantly but the actual octane increase cannot be determined without an examination of all fuel components.

phat68 · Post by **phat68** » Sat Oct 03, 2009 5:39 am

Xlyene works also, if you have no dettonation you don't need the booster

shoedoos · Post by **shoedoos** » Sun Oct 04, 2009 4:10 pm

David Redszus - have you got a more specific percentage as far as a "splash" of leaded is concerned?

mach1charlie · Post by **mach1charlie** » Sun Oct 04, 2009 9:35 pm

100 LL avation fuel, really has a lot of lead in it compared to highway fuel.

Benzine is bad stuff. Know a guy who had a heart attack in his 40s. Doc asked "ever been exposed to benzine ?" he had been mixing his own fuel.

Toulene is a good octane booster. has been used straight for fuel (honda).

Acetone will let you blend nitro with gas.

mach1charlie

David Redszus · Post by **David Redszus** » Tue Oct 06, 2009 12:57 pm

shoedoos wrote:David Redszus - have you got a more specific percentage as far as a "splash" of leaded is concerned?

Unfortunately, it is not possible to calculate the octane increase due to the addition of lead to gasoline unless the exact compositon of the gasoline is known.
The reason is that lead will react with each fuel component in a different way. Lead added to some components will significantly increase octane, some will be insensitive and with some, octane will actually be reduced.

As a very general guide (very, very general) you could use a weighted average. The addition of 10% leaded race fuel added to pump gas will raise the octane index by about one full point, i.e, 93-->94.

As a matter of record, AvGas does not contain a high level of lead. The highest levels of lead are found in very high octane (118-119) race fuels.

Dodge Freak · Post by **Dodge Freak** » Tue Oct 06, 2009 10:27 pm

I thought a tiny bit of lead did help boost octane a bit. When I mean tiny its like .01% or .001% Unleaded gasoline used to be like that until the mid 90's I believe, them for 1996 emission controls got so advance all lead had to be out of gasoline.

I believe I have the dates right, its been awhile but still recall it well--unless it was in the mid 80's. Might be mid 80's cause I recall an older guy and me talking about it then and its been very long since I seen him last.

David Redszus · Post by **David Redszus** » Sat Oct 10, 2009 12:07 am

Once upon a time, the addition of leaded fuel to unleaded fuel would raise the octane to a higher level than either individual component. Those days are now gone since the fuel components have changed and are much less sensitive to the addition of lead.